Failing to reduce emissions will cost NZ 'huge amount' - Labour

Chinese President Xi Jinping (C) shakes hands with US President Barack Obama and UN Secretary General Ban Ki-moon (Reuters)

Labour's putting pressure on the Government now that the US and China have ratified the Paris Agreement on climate change.

They've beaten New Zealand most countries to it, and Labour climate spokeswoman Megan Woods says our Government needs to put a plan in place.

"What is absolutely important for New Zealand now is not only the ratification side, but making sure we get our domestic policies in place to actually reach the targets that we're signing up for."

Ms Woods says there's no comprehensive plan in place to reduce emissions.

"What New Zealand has to do now - and Treasury sounded warning bells about this a couple of years ago - is we actually have to reduce emissions or it's going to cost a huge amount of money to buy our way out of it."

US President Barack Obama says his country is putting its money where its mouth is.

Until now, the countries that had ratified the Paris agreement accounted for just over 1 percent of carbon emissions. But the inclusion of the two superpowers pushes that figure up to 40 percent.

US President Barack Obama says his country is putting its money where its mouth is.

"Today we are moving the world significantly closer to the goal we have set," said Mr Obama.

With China and the US on board, 26 countries have ratified December 2015's agreement.

"With China and United States now ratifying the Paris agreement, the New Zealand Government has nowhere to hide," said Greenpeace New Zealand executive director Russel Norman.

Climate Change Minister Paula Bennett was unavailable for comment on Sunday, but has said before the Government plans to ratify the agreement by November.

"There will be reputational damage to countries that don't reach their targets," says Ms Woods.